3-nitrotyrosine (3-NT) is a biomarker closely associated with the early diagnosis of oxidative stress-related disorders. The development of an accurate, cost-effective, point-of-care 3-NT sensor holds significant importance for self-monitoring and clinical treatment. In this study, a selective, sensitive, and portable molecularly imprinted electrochemical sensor was developed. ZIF-67 with strong adsorption capacity was facilely modified on an electrochemically active laser-induced graphene (LIG) substrate (formed ZIF-67/LIG). Subsequently, biocompatible dopamine was chosen as the functional monomer, and interference-free ʟ-tyrosine was used as the dummy template to create molecularly imprinted polydopamine (MIPDA) on the ZIF-67/LIG, endowing the sensor with selectivity. The morphologies, electrochemical properties, and detection performance of the sensor were comprehensively investigated using scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. To achieve the best performance, several parameters were optimized, including the number of polymerization cycles (15), elution time (60 min), incubation time (7 min), and pH of the buffer solution (6). The turnaround time for this sensor is 10 min. Benefiting from the alliance of MIPDA, ZIF-67, and LIG, the sensor exhibited excellent sensitivity with a detection limit of 6.71 nM, and distinguished selectivity against 11 interfering substances. To enable convenient clinical diagnosis, a customized electrochemical microsensor with MIPDA/ZIF-67/LIG was designed, showcasing excellent reliability and convenience in detecting biological samples without pretreatment. The proposed microsensor will not only facilitate clinical diagnosis and improve patient care, but also provide inspiration for the development of other portable and accurate electrochemical biosensors.

中文翻译：

---

开发基于分子印迹聚多巴胺/ZIF-67/激光诱导石墨烯的选择性电化学微传感器，用于即时测定 3-硝基酪氨酸

3-硝基酪氨酸（3-NT）是一种与氧化应激相关疾病的早期诊断密切相关的生物标志物。开发准确、经济高效的即时护理 3-NT 传感器对于自我监测和临床治疗具有重要意义。在这项研究中，开发了一种选择性、灵敏且便携式的分子印迹电化学传感器。具有强吸附能力的ZIF-67可以在电化学活性激光诱导石墨烯（LIG）基底上轻松修饰（形成ZIF-67/LIG）。随后，选择生物相容性多巴胺作为功能单体，并使用无干扰的ʟ-酪氨酸作为虚拟模板，在ZIF-67/LIG上创建分子印迹聚多巴胺（MIPDA），从而赋予传感器选择性。利用扫描电子显微镜、循环伏安法、电化学阻抗谱和微分脉冲伏安法全面研究了传感器的形貌、电化学性能和检测性能。为了获得最佳性能，优化了多个参数，包括聚合循环数 (15)、洗脱时间 (60 分钟)、孵育时间 (7 分钟) 和缓冲溶液的 pH 值 (6)。该传感器的周转时间为 10 分钟。得益于 MIPDA、ZIF-67 和 LIG 的联合，该传感器表现出优异的灵敏度，检测限为 6.71 nM，并对 11 种干扰物质具有出色的选择性。为了方便临床诊断，设计了一种采用MIPDA/ZIF-67/LIG的定制电化学微传感器，在无需预处理的情况下检测生物样品时表现出出色的可靠性和便利性。所提出的微传感器不仅有助于临床诊断和改善患者护理，而且还为其他便携式、精确的电化学生物传感器的开发提供灵感。